Pyrimidine azo dyestuffs



PYRHVIIDINE AZO DYESTUFF S Karl Taube, Leverkusen-Bayerwerk, Germany, assignor to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany N Drawing. Application April 30, 1952, Serial No. 285,303

Claims priority, application Germany May 7, 1951 8 Claims. (Cl. 260154) The present invention relates to new azo dyestuifs and to a method of making the same; more particularly it relates to azo dyestuffs corresponding to the general formula:

I- HO.(]3-N.R art ax] In this formula R stands for the radical of a diazo or tetrazo compound of the benzene or naphthalene series, R stands for hydrogen, alkyl or aryl, X stands for -OH, -"SH, NH2 or -NH.CN, and n means 1 or 2.

The invention further relates to the metal complex compounds of such azo dyestuffs corresponding to the above general formula, as form metal complex compounds on account of their constitution i. e. if the radical R bears a metal complex forming group in ortho-position to the -N:N-bridge.

The new azo dyestuffs which according to the above formula are monoand disazo dyestuifs, can 'be obtained by coupling diazo or tetrazo compounds of the benzene or naphthalene series with derivatives of 4-hydroxy-6- imino-pyrimidine which can be represented by the formula:

wherein R and X have the same meaning as above. Such derivatives of 4-hydroxy-G-imino-pyrimidine are .e. g. 2,4- dihydroxy-6-imino-pyrimidine, 3 phenyl-2,4-dihydroXy-6- imino-pyrimidine, 3-methyl-2,4-dihydroxy-G-imino-pyrimidine, 2 -thiol-4-hydroXy-6-imino-pyrimidine, 3-phenyl-2- thiol-4-hydroxy-6-imino-pyrimidine, 2 cyanamino 4-hydroxy-6-imino-pyrimidine. in case the diazo or tetrazo compounds used contain in ortho-position to the diazotized amino group or groups a metal complex forming group e. g. a hydroxy group, alkoxy group or a carboxylic group, the monoor disazo dyestufis thus obtained may be converted into their metal complex compounds by known methods.

According to the substitution or non-substitution of the diazo or tetrazo components by sulfonic and/ or carboxylic acid groups the new dyestuffs are suited for dyeing wool, cotton, fibres of regenerated cellulose, paper -or as pigment dyestuffs. The new dyestufis yield on the named fibrous materials .full and clear yellow shades of good fastness to alkali and acid. Though it was known that barbituric acid can couple to form azo dyestulfs, it could not be foreseen that also its derivatives of the type used according to the present invention would couple and yield dyestuffs of the mentioned qualities.

The following examples illustrate the invention, without, however, limiting it thereto.

Example 1.21.7 grams A mol) of l-aminobenzene-2-carboxylic-5-sulfonic acid are stirred in 200 cc. of ice-water with 25 cc. of technical hydrochloric acid and diazotized with 6.9 grams of sodium nitrite. The disazo compound is added to a solution of 12.7 grams A mol) of 2,4-dihydroxy-6-iminopyrimidine in 500 cc. of water and 30 grams of sodium carbonate. The yellow monoazo dyestuif thus formed is separated by adding sodium chloride, isolated and dried. It dyes wool clear yellow shades. The dyestuff corresponds as free acid to the formula:

Example 2.-l2.7 grams mol) of 2,4-dihydroxy- 6-imino-pyrimid-ine are dissolved in 500 cc. of water with 30 grams of sodium carbonate, and 25 grams A mol) of the diazo compound of 1-aminc-2 hydroxyn'aphthalene-' 4-sulfonic acid are added. The moncazo dyest-uff thus formed is isolated and converted into the chromium complex compound by refluxing it with chromium acetate in acetic acid solution. The chromium-containing dyestuif is isolated in the usual manner and dyes wool from the sulfuric acid bath clear bluish-red shades. The chromiumfree dyestuff corresponds as free acid to the formula:

Example 3.-40.2 grams mol) of 3,3-diaminodiphenyl urea-4,4'-disulfonic acid are tetrazotized in 500 cc. of water with 50 cc. of technical hydrochloric acid and 13.8 grams of sodium nitrite. The tetrazo solution Example 4.21.7 grams mol) of l-aminobenzene-Z-carboxylic-4-sulfonic acid are stirred into 200 cc. of ice-water with 25 cc. of technical hydrochloric acid and diazotized with 6.9 grams of sodium nitrite. The diazo compound is run into a solution of 15.2 grams mol) of 4-hydroxy-6-imino-2- cyanaminopyrirnidine in 500 cc. of water and 30 grams of sodium carbonate. The monoazo dyestufi is salted out by means of sodium chloride, isolated and dried, and is obtained as a yellow powder which dyes paper from aqueous solution very clear greenish-yellow shades fast to light. The dyestutf corresponds as free acid to the formula:

A dyestutf of similar properties is obtained by using 1-aminobenzene-Z-carboxylic-5-sulfonic acid instead of laminobenzene-2 carboxylic-4-sulfonic acid.

Example 5.-25.3 grams i mol) of l-aminobenzene-2,5-disulfonic acid are diazotized in 250 cc. of ice- Eater winizs c2. of hydrochloric acid and 6.9 grams of sodium nitrite. The diazo solution is run into 20.3 grams ;i mol) of 3-phenyl-2,4-dihydroxy-6-irninopyrirnidine in 300 cc. of water and 30 grams of sodiurnicarbonater The tiionoazo dyestuff is isolated in the ii'sual manner and dyes y vo'o'l yellow shades. The dyestdfi corresponds as free acid to the formula:

soar

nocamonn N=N-o 0.011

HN= -N s 0 H I claim: i 1. A20 dyestufls of the general formula I- 1'10 .C-NH

wherein R stands for a radical of the benzene series hearing at least one substituent selected from the group consisting of 40 1-1, COOH and alkali salts thereof.

3. A20 dyestuffs of the general formula wherein R stands for a radical of the @benzene series hearing at least one snbsti-tuent selected from rthe group consisting of SO3-H, -'COOH and alkali salts thereof.

'4. The monoazo dyestufi corresponding as free .acid to the formula:

. H'0is-QN=N-g i lness medal coon dyeing paper very clear greenish yellow shades 'fast to light.

the formula:

5. The monoazo dyestufi corresponding as free acid to dyeing paper very clear greenish yellow shades fast to h 6. The monoazo dyestuff corresponding as free acid to the formula:

son-1 HO;G''NH NrN+0 (Eon HN=, -N

7. The disazo dyestufi corresponding as free acid to the formula:

N N NE i i OH NH it on that that l= ls laces.

its is (In is '8. The menoazo dyestuff corresponding as free acid to the formula:

References Cited in the file of this patent UNITED STATES PATENTS 2,140,536 McNally et al. Dec. 20, 1938 2,578,290 Dickey et al Dec. 11, 1951 FOREIGN PATENTS Great Britain Sept. 9, 1926 

1. AZO DYESTUFFS OF THE GENERAL FORMULA 